John, Yes the fired cases will re-enter the chamber, freely.
My loaded rounds using .380 dia. bullets measure .397 before going into the sizing die.
This is what led me to believe, back at the start of my loading for the Target model, that the factory was using .375" bullets, since the factory ammo measures .392 O.D at the case mouth. My chamber is .401 at that point, as measured by snap-mike, so it's an inferral not actual measurement.
I need to do another cast of my chamber. The thing is, I've got a good thing going with what amounts to a tight-neck chamber when using the .380" bullets. Now that I've got the powder measure issue worked out I believe I'll be shooting tight groups when I get around to the 38-55 again(after about another 2000 varmint rounds are finished).
